The effects of chronic zoledronate usage on the jaw and long bones evaluated using RANKL and osteoprotegerin levels in an animal model.

The discovery of the receptor activator of nuclear factor kappaB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) system (RANK/RANKL/OPG system) has been one of the most important advances in bone biology in the last decade. We investigated how the chronic application of bisphosphonate affects the RANKL and OPG levels in an animal model and whether this effect may be related to bisphosphonate-related osteonecrosis of the jaws (BRONJ). Thirty female Sprague-Dawley rats were used in this study. The rats were randomly divided into three groups (10 in each): Z, the zolendronate group, injected with zolendronate for 10 weeks; S, a control group, injected with saline solution for 10 weeks; and C, a control group, in which no injection was given. RANKL values in the tibia were increased in the Z group when compared with the two controls; however, the RANKL values in the mandible were decreased when compared with the controls. Although the differences did not reach statistical significance, the mandibular OPG values were increased in the Z group when compared with the C and S groups. The mechanism of RANKL negation and absence in osteoclastic activation could be a predisposing factor for the development of BRONJ.

Serum ischaemia-modified albumin increases in critical lower limb ischaemia.

BACKGROUND: Ischaemia is a common phenomenon in the pathogenesis of a wide range of medical and surgical conditions, including myocardial infarction, mesenteric vascular occlusion and compartment syndrome. Ischaemia modified albumin has been suggested as an aid to clinical decision making in various clinical settings. This study examines the usefulness of IMA in the diagnosis of limb ischaemia (LI). METHODS: This case-controlled study was performed in the emergency department of Karadeniz Technical University Hospital, Turkey. 22 patients presenting to the emergency departments and definitively diagnosed with LI were enrolled in the study. A control group of 22 healthy volunteers served as a reference for biochemical parameters. RESULTS: The mean serum IMA level for LI patients was 0.295 (SD 0.062) ABSU. The mean serum IMA level for control patients was 0.174 (SD 0.061) ABSU. There was a statistically significant difference between the mean LI patient and mean control patient IMA levels (p<0.0005). A ROC curve analysis reveals the relationship between sensitivity and specificity for IMA in limb ischaemia. CONCLUSION: There is a significant increase in serum IMA in limb ischaemia. Furthermore, using a cutoff of 0.22 ABSU, ROC curve analysis shows that IMA is 81.8% sensitive and 81.8% specific 81.8% in patients with clinically severe lower limb ischaemia. Future studies would be needed to determine if IMA would be clinically useful in the diagnosis of subtle limb ischaemia.

Genotoxicity studies on benzimidazole retinoids.

Retinoids consist of a family of naturally occuring compounds including all-trans retinoic acid (ATRA), retinal, retinol (vitamin A), 9-cis retinoic acid, 13-cis retinoic acid as well as a large number of synthetic derivatives. Retinoids are known to elicit diverse pharmacological profiles such as controlling cell differentiation/proliferation and modulating specific premalignant lesions and reducing second primary tumors in patients. Clinical use of retinoids is limited due to their toxicity. Three benzimidazole retinoid derivatives (BITN, BITNm, BITNe) were synthesized and were examined in terms of genotoxicity towards human lymphocyte cultures by sister chromatid exchange (SCE) analysis. It has been found that BITN decreased the number of SCEs 20% at 10(-6) M, but had no effect at 10(-5) M. No significant effect on SCEs was observed for BITNm and BITNe at both concentrations. ATRA increased the SCEs (35%) at 10(-5) M but had no effect at 10(-6) M. The results have shown that benzimidazole retinoids did not induce SCE significantly. Besides this, BITN reduced the SCEs and had a protective effect at low concentration. Since the induction of glutathione S-transferase (GST) is associated with anticancer drug resistance, the effects of BITN, BITNm, BITNe and ATRA on human lymphocyte GSTs were also investigated using CDNB as substrate. BITN and BITNm induced GST activities 54% and 49% respectively at 10(-5) M, but had no effect at 10(-6) M. BITNe induced GST activity 62% at 10(-5) M and 35% at 10(-6) M. ATRA had no effect on GST activity at 10(-5) M.

Periradicular lymphoma: differentiation from inflammation.

Although endodontists concern themselves primarily with inflammatory disease, constant vigilance should be maintained so that the diagnosis of periradicular malignant disease is not delayed. This article reviews oral lymphoma and presents two cases that illustrate the difficulty that can be encountered in establishing a timely and accurate diagnosis. Suggestions for maximizing the chances of early differentiation of inflammatory from malignant disease are presented. The role of the biopsy and its limitations are offered.